Animal collective motion is a natural phenomenon readily observable in various taxa. Although theoretical models can predict the macroscopic pattern of group movements based on the relative spatial position of group members, it is poorly understood how group members exchange directional information, which enables the spatial coordination between individuals during collective motion. To test if vocalizations emitted during flocking flight are used by birds to transmit directional information between group members, we recorded vocal behaviour, head orientation and spatial position of each individual in a small flock of zebra finches (Taeniopygia guttata) flying in a wind tunnel. We found that the finches can use both visual and acoustic cues for three-dimensional flock coordination. When visual information is insufficient, birds can increasingly exploit active vocal communication to avoid collisions with flock mates. Our study furthers the mechanistic understanding of collective motion in birds and highlights the impact interindividual vocal interactions can have on group performances in these animals.

动物集体运动是在各种分类群中很容易观察到的自然现象。虽然理论模型可以根据群体成员的相对空间位置来预测群体运动的宏观模式，但人们对群体成员如何交换方向信息，从而在集体运动过程中实现个体之间的空间协调却知之甚少。为了测试鸟类在成群飞行期间发出的声音是否被用来在群体成员之间传递方向信息，我们记录了一小群斑胸草雀（Taeniopygia guttata ）中每个个体的声音行为、头部方向和空间位置。) 在风洞中飞行。我们发现雀类可以使用视觉和听觉线索来进行三维鸡群协调。当视觉信息不足时，鸟类可以越来越多地利用主动的声音交流来避免与鸟群伴侣发生碰撞。我们的研究进一步加深了对鸟类集体运动的机械理解，并强调了个体间的声音相互作用可能对这些动物的群体表现产生的影响。